DE102009023507A1 - Screw type compressor aggregate i.e. pressurized air compressor aggregate, has pressure line exhibiting trap, where proportion between common geometrical chamber volumes in front of trap is larger than dimension of operating chamber - Google Patents

Abstract

The aggregate has an oil separator (18) connected with a screw type compressor via a pressure pipeline (20). The pressure pipeline exhibits a trap between a pressure chamber of the compressor and the oil separator in channel parts that are attached to the pressure chamber. A top flow path at a vertical deflection point lies deeper than deepest point of an outlet of the compressor in the trap, where proportion between common geometrical chamber volumes in front of the trap is larger than geometrical dimension of a V-shaped operating chamber at beginning of opening of an outlet.

Description

The The invention relates to a screw compressor unit with an oil-flooded Screw compressor, a drive motor, an oil system, at least consisting of oil separator with oil collector, oil filter and a duct or piping system that communicates having the screw compressor and other peripheral devices, such as oil cooler, may own. Of the Screw compressor with internal compression, has at least two pairwise intermeshing parallel screw rotors, having the crests and grooves, the crests and grooves of the two rotors along a common engagement line in sealing mesh and the grooves through the intervention line are separated from each other. This will form V-shaped working chambers, by a housing be enclosed, which consists of a shell wall and end walls with controllable by the ridge and end profile edges of the rotors Inlets and outlets for the working medium exists. The inlets and outlets close suction chamber and pressure room. In front of the suction chamber is upstream one Power control device arranged, with the help of the compressor to be promoted mass flow regulated to the value zero can be.

shell wall and end walls of the compressor housing form a Cavity through at least two parallel, intersecting holes, in which the screw rotors with their V-shaped working chambers are arranged.

at Rotary movement of the rotors increase the suction side V-shaped working chambers on the communicating with the suction chamber standing side, causing working fluid in these gaps between the teeth Suction chamber flows through one or more inlets.

On the other side of the common line of action shrink during rotary motion the v-shaped working chambers, so that a compression of a compressible working medium take place can.

Around to cool the compression process, the inner seal along the line of intervention to improve and in direct Greasing mesh rotors becomes oil injected into the decreasing v-shaped working chambers, that together with the working medium through the outlets in the pressure chamber is promoted, hence the term "oil-flooded" screw compressor.

ever according to the position of in the pressure-side housing end wall fixed outlet control edges of one or more outlets, the beginning of the opening of a V-shaped working chamber for Define pressure chamber, one of the state of the working medium at the beginning of compression dependent pressure in the V-shaped Working chamber at the time of opening this result, the regardless of the pressure in the pressure chamber is greater, may be equal to or less than this. The opening time corresponds to the angular position of at least one rotor in the a communicating connection from itself as a result of rotor rotation shrinking V-shaped working chambers to the outlet arises.

The geometric relationship between the gullet volumes the V-shaped working chambers at the time of separation from the suction side due to rotor rotation and the tooth space volumes at the time of opening the pressure side V-shaped Working chambers to the outlet is the geometric inner volume reduction ratio Vi. The value Vi becomes for the full load operation of the screw compressor executed so that the sum of the losses is minimized and the compressor has the highest efficiency. The inner one Compaction, which is significantly caused by the Vi value, achieves one with respect to the pressure in the pressure line of the compressor optimal value.

In order to change the delivery volume of the screw compressor unit with a Saugdruckdrosseleinrichtung is the control device the suction side of the compressor more or less closed, so that the mass flow due to the throttle relaxation of the working medium in the control device more or less changes. With zero funding, Part load operation without promotion of working medium in the Downstream pressure lines, is the Saugdruckdrosseleinrichtung completely closed.

Of the Compressor does not convey working medium, but only the injected into the working chambers and other oil Functional oil flows, for example, for lubrication the radial and axial bearings of the rotors in the compressor needed and also in closed tooth spaces be directed.

These Regulation by Saugdruckdrosseleinrichtung conditions that the achievable by internal compression pressure ratio reduced with increasing throttling.

The internal compression selected for full load operation is not enough to the internal pressure before opening the Discharge or the outlets to raise sufficiently. consequently flow through working fluid and oil due to the the rotor rotation opening outlets from the pressure chamber back to the V-shaped working chamber.

If the pressure chamber downstream channel parts or the pressure line is not arranged with a slope away from the compressor can be, escapes the working medium up and it mostly returns oil in the opening working chambers, the immediately again by the volume reduction proceeding with further rotor rotation the V-shaped working chamber is ejected. At zero funding only oil oscillates between tooth gaps and Pressure chamber.

The generates hydraulic pulsations in the downstream Channel parts and in the pressure line.

Especially at high external pressure conditions, calculated from final pressure divided by suction pressure, occur as a result the large pressure differences between the internal pressure of the Working medium immediately before opening the outlet opening in the V-shaped working chamber and the with the outlet in Connecting pressure chamber on dynamic pressure pulsations, the reliability of the compressor and the entire pressure booster compromise.

task The invention is to eliminate this disadvantage and oil Keep away from the pressure chamber.

According to the invention proposed that the pressure line on the compressor unit between the pressure chamber or the adjoining the pressure chamber channel parts or Pipelines are designed so that downstream a vertical deflection of the flow direction in one so-called traps, so that before the trap even at zero production a gas cushion is present, as through the liquid seal in the trap no gas can flow. In the operating mode with open suction throttle controller become oil and working medium First pressed down as far as the working medium can flow through this section. That's the case, though the oil level is lowered below the uppermost deflection point is.

The Geodetic height of the uppermost turning point of the Traps is smaller than the geodesic height of the Lower edge of the pressure chamber.

The common geometric chamber volume up to the trap, formed from Pressure chamber size and channel part size or pipe section size is advantageous a multiple of the geometric size of the V-shaped Working chamber at the beginning of opening the outlet.

invention Multiples are in rough approximation values between 5 and 100th

The larger values of the multiple become larger Assigned to pressure ratios.

The Ratio of common geometric chamber volume and volume of the V-shaped working chamber at the beginning of opening the outlet significantly determines the size the pressure pulsation within the section of the common geometric Chamber volume at constant speed.

The Size of the pressure pulsation within the section the common geometric chamber volume up to the trap is as well depending on the built-in Vi and the speed of sound of the working medium.

The Size of this pressure pulsation before the trap is the stimulus for the pipeline section that is followed by the trap.

The Embodiment of the invention reduces pressure pulsations to an acceptable level.

By the embodiment of the invention with a trap Ensures that the oil is also at zero production pressed by means of bypass working fluid from the pressure chamber and there is always working medium in the pressure room that is in the tooth gaps flow back.

The Amplitudes of the forced oscillation are reduced to such an extent that the compressor at part-load operation down to zero promotion safe to work.

The Invention will be closer to an embodiment but it should not be limited to this be. In the accompanying drawings show:

1 a longitudinal section of a known compressor design with suction pressure regulator according to patent application with the file number DE 102009016790.0

2 a diagram of a known embodiment of a compressed air compressor unit with a pressure control valve, which uses the pressure of the suction-side control valve as a control pressure and a rising in the direction of flow pressure line.

3 an embodiment of the invention a Druckluftverdichteraggregates with a pressure control valve, which uses the pressure of the suction-side control valve as a control pressure and a rising in the flow direction pressure line with built-in traps.

4 an embodiment of the invention a rising in the flow direction pressure line with a trap as a housing design.

The Invention is not limited to the example shown.

For the sake of descriptive simplicity, an example was first chosen in which the Traps 29 is arranged outside the compressor housing in the pressure line.

Of the Traps, integrated into the compressor housing, can be part of it the pressure housing or other cavities in the compressor be, which flows through the invention become. The Traps can also be used as an additional housing be arranged adjacent to the pressure chamber and flows through the invention become.

The Design features of the trap are not exhausted.

For example can also be a drain pipe, the opening pointing down, arranged in a relation to the pressure chamber deeper housing area be whose opening is arranged so that the inventive Function of a trap is met. Also, the drainpipe can be arranged in another pipe section of the pressure line so that the described function of a trap is fulfilled.

According to 1 the compressor has a housing which, among other things, the suction chamber 1 , the housing shell wall 8th and the pressure-side end wall 4 has. The suction room 1 is over an inlet 2 with V-shaped working chambers 3 connected. The V-shaped working chambers decrease as a result of the rotation of the main rotor 6 and the meshing side rotor 14 , They are after appropriate rotation of the two rotors via the outlets 5 with the pressure room 9 connected so that the working fluid in the pressure line 20 flows.

The outlets 5 have a radial and an axial portion.

In the housing shell wall 2 are a main rotor 6 and an unrepresented secondary rotor arranged in coaxial position of its axes of rotation to the bore axes. When the rotors rotate, they increase with the suction chamber 1 communicating V-shaped working chambers, thereby adding working fluid into these tooth spaces from the suction space 1 over the inlet 2 flows. On the other side of the plane containing the rotor axes of rotation, the V-shaped working chambers shrink during rotation, so that compression takes place, the compression end pressure, the internal pressure, the geometric volume reduction ratio Vi and the state of the working medium in the suction space 1 of the compressor depends.

The condition of the working fluid in the suction chamber 1 the compressor changes when the compressor is operated at partial load because the pressure behind the suction pressure regulator 11 decreases.

The internal pressure of the working fluid due to internal compression decreases with increasing throttling of the suction pressure regulator 11 ,

By returning working fluid from the high pressure side, the outlets decrease at the time of opening 5 the pressure difference between pressure chamber 9 and internal pressure.

2 shows the arrangement of the controllable bypass channel 19 as in the patent application with the file number DE 102009016790.0 described. They are pressure vessels / oil separators 18 and inlet 7 shown.

By this configuration flows over the bypass channel 19 Working fluid into the tooth spaces if the internal pressure at the beginning of the discharge process is too low relative to the discharge pressure of the system as a result of the suction pressure restriction.

This promotes the compressor despite zero promotion, ie closed suction pressure regulator 11 Working fluid in a bypass in the pressure chamber 9 , so that oil and working fluid the pressure chamber 9 happen.

According to 3 is the pressure line on the compressor unit according to the invention between the pressure chamber and pressure tube to the oil separator 31 initially downstream with a vertical diverter, the trap 29 equipped so that a liquid seal is present. The working fluid first presses the oil level down during operation of the compressor until the oil level is lowered below the uppermost deflection point.

The geodetic height of the upper channel part of the trap is approximately the liquid level 30 during operation of the compressor unit with zero delivery of the compressor (suction pressure regulator 11 closed).

The geodetic height of the liquid level 30 is smaller than the geodetic height of the lower edge of the pressure chamber 9 ,

The common geometric chamber volume up to the trap 29 , formed from the geometric volume of the pressure chamber 9 and from geometric pipe section to liquid level 30 of the trap 29 is 20 times the geometric size of the V-shaped working chamber at the beginning of opening the outlet for 27 bar compression end pressure and 1500 l / min.

The Amplitudes of the forced oscillation are reduced to such an extent that the compressor at part-load operation down to zero promotion safe to work.

The 4 shows the traps 29 as in a housing design. With the liquid level 30 which is realized by a stable rib.

1

suction

2

inlet

3

working chamber at intake pressure

4

pressure side end wall

5

outlets

6

main rotor

7

inlet opening the controlled bypass channel on the compressor housing

8th

Housing casing wall

9

pressure chamber

10

suction end wall

11

Suction pressure

12

V-shaped working chamber

15

controllable Bypass control valve

18

Pressure vessel oil separator

19

controllable bypass channel

20

pressure line

29

traps

30

liquid level during compressor operation

31

pressure pipe to the oil separator

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 102009016790 [0028, 0043]

Claims (5)

Screw compressor unit with an oil-flooded screw compressor, a drive motor, an oil system, at least consisting of oil separator with oil collector, which are communicatively connected via a pressure line to the compressor and the pressure line is arranged rising in the flow direction, further consisting of oil filter and a duct or piping system, the having communicating connections with the screw compressor, wherein the screw compressor, from at least two mutually intermeshing, parallel screw rotors having combs and grooves, a housing comprising a shell wall and end walls with controllable from the comb edges of the rotors inlets and outlets for the working medium , which connect suction chamber and pressure chamber, and shell wall and end walls enclose a working space, which by at least two parallel, intersecting housing housing in which the screw rotors angeor dnet, is formed and with a flow control device, which is arranged as a controllable throttling and / or shut-off before the inlet, characterized in that the pressure line on the compressor unit between the pressure chamber of the compressor and oil separator in the pressure chamber adjoining the channel parts or piping downstream a substantially vertical flow direction redirecting means, a trap, in which the uppermost flow paths at the vertical deflection point geodetically lower than the lowest point of the compressor outlets, and the ratio between common geometric chamber volume before the trap, formed from pressure chamber size and channel parts or Pipe sections, greater than the geometric size of a V-shaped working chamber at the beginning of opening the outlet. Screw compressor according to claim 1, characterized that height of the possible uppermost flow path in traps at geodetic rating is smaller than that Geodetic height of the lower edge of the pressure chamber of the Compressor. Screw compressor according to claim 1, characterized that the common geometric chamber volume before the trap, formed from Pressure chamber size and channel part size or pipe section size many times the geometric size of the V-shaped Working chamber at the beginning of opening the outlet is. Screw compressor according to claim 3, characterized that multiples the geometric size of the V-shaped Working chamber in the range between 5 and 100 are. Screw compressor according to claim 4, characterized that larger values of the multiple greater Pressure ratios are assigned.